Kidney transplant recipients routinely are required to take glucocorticoids for immunosuppression. Prednisone has several side effects which may negatively impact on long term health and quality of life. These side effects include increased cardiovascular risk, muscle weakness, and excessive weight gain. We propose to study 40 patients who are randomly assigned to a prednisone withdrawal protocol. This study is an ancillary study to a larger multicenter prednisone withdrawal protocol in which the prednisone withdrawal randomization is double blinded, with those in the withdrawal group taking placebo. Our study will assess the effects of prednisone withdrawal on muscle structure and function, body composition, exercise capacity, quality of life, and cardiovascular risk profile. Patients will be tested at baseline (3 months post transplant) and again at 1 year post transplant. The testing includes: muscle biopsy with analysis of fiber type, size, capillary density, and electron microscopy analysis of microstructure; muscle function using isokinetic muscle testing; exercise capacity using maximal treadmill testing with respiratory gas analysis; body composition using DEXA for analysis of body fat%, muscle mass, and bone density; quality of life assessment using the MOS questionnaire; and cardiovascular risk profile using the Framingham CV risk algorithm. The results of this study will assist in the understanding of medication side effects and provide a basis for development of interventions which may also impact several of the study outcomes. We propose to study muscle function, exercise capacity and cardiovascular risk in two groups of kidney transplant recipients: one group randomly assigned to prednisone withdrawal and another group on maintenance prednisone therapy. This proposal will involves testing which includes: cardiorespiratory fitness, muscle strength and endurance, body composition, muscle biopsy will be obtained for analysis of microstructure and enzyme content, cardiovascular risk profile will be assessed using the Framinham algorithm, health-related quality of life will also be assessed.